Sadly, synapse is orphaned, Kupfer hasn't had a commit in over a year and GNOME-Do is going nowhere since GNOME Shell does the same thing by itself. One thing that's kept me from more minimal environments than those with their own launcher is that's there's just no really good standalone launcher.
Synapse may not have an active upstream any more, but, well, the Ubuntu package is still well-maintained (in the synapse-core/testing ppa), and it does everything I need it to.
An aversion to orphaned software is clearly good for things at a security boundary (web browsers, sshd, etc), but is it really an issue for a launcher? In 3-5 years it may not be good enough, but shrug, if that's the case I'll have another look around then. It's not like launchers have lock-in.
